Conventionally, a gas barrier film with a relatively simple structure, which is formed with an inorganic film such as a vapor deposition film of metal or metal oxide on a surface of a resin substrate to prevent permeation of water vapor and gas such as oxygen, has been used in the field of food product, packaging materials, pharmaceutical products, and the like.
Recently, a gas barrier film for preventing permeation of water vapor, oxygen, or the like is also applied for the field of electronic devices such as a liquid crystal display element (LCD), a solar cell (PV), or an organic electroluminescence (EL). In order to impart flexibility and a light and non-brittle property to such electronic devices, a gas barrier film with high gas barrier property is required instead of a glass substrate which is hard and easily breakable.
As a method for obtaining a gas barrier film which can be applied to an electronic device, a method of forming a gas barrier layer on a substrate such as film by performing a plasma CVD method (Chemical Vapor Deposition: chemical vapor phase growing method, chemical vapor deposition method) on a resin substrate, and a method of forming a gas barrier layer by performing a surface treatment (modification treatment) after coating a coating liquid containing polysilazane as a main component on a substrate are known.
For example, in JP 2009-255040 A, for the purpose of achieving both thickening a gas barrier layer for obtaining high gas barrier property and suppressing cracks in a thickened gas barrier layer, a technique of laminating a thin film on a substrate by performing, at least two times, each of a step of forming a polysilazane film according to wet coating of a liquid containing polysilazane and a step of irradiating the formed polysilazane film with vacuum ultraviolet ray is disclosed.
Furthermore, in JP 2012-148416 A, a barrier film having improved scratch resistance which is obtained by adding a transition metal to a silicon-containing film is disclosed.